Every day, you wake up, eat breakfast, and begin the day. With a little caffeine from a cup of coffee or tea to get a jumpstart, you shed off sleep and tackle the work day. But you may not always run on optimal energy. You might suffer from a level of tiredness or fatigue that just can’t be shaken off with a hot espresso or morning jog.
And the problem might lie in the gut.
Our gut is intricately tied to our overall well-being, as we touched on in our previous introductory article on gut health. The gut is so powerful that it can even affect our moods and thinking through the gut-brain axis. But what about our energy levels? Research shows that the gut, as our main channel for receiving nutrition, can impact our energy in surprising ways.
People living with less energy and more fatigue on a daily basis may be experiencing changes to their gut microbiome. The microorganisms that reside in the gut can influence how a person digests and absorbs their food, induce irritations and inflammation in the gastrointestinal tract, and affect our sleep cycles. All of these factors play a role in how energetic we feel during the day.
The Gut Microbiome and Fatigue
Growing evidence suggests we may be more tired or exhausted from alterations in our gut. Low energy levels can be accompanied by a viral infection or a flu-like illness. Researchers speculate that some kind of change impacts the gut, whether that’s an infection or a source of stress, can cause a shift in the microbial community to shift from mostly beneficial bacteria living in the gut to a sudden growth of bacteria, such as pathogenic E. coli. These bacteria create an imbalance in the gut and give us more gastrointestinal trouble on a daily basis.
Other bacteria involved in these alterations of the microbiome include Enterococcus and Streptococcus species, bacterial genera that are associated with human infections. Proteus bacteria, a genus of bacteria that causes urinary tract infections, wound infections, and meningitis in babies, is highly present in the gut microbial ecosystem of patients with high levels of fatigue. Overall, individuals that experience a lot of fatigue tend to exhibit less bacterial diversity in their gut.
The Link Between Gut Inflammation and Feeling Tired
These pathogenic bacteria generate byproducts that trigger the intestinal lining and immune system to release pro-inflammatory signaling molecules to fight the threat of infection, creating an environment of low-grade inflammation in the gut. Much like how someone might feel exhausted after getting hit by the cold or flu, the body shuts down in the face of this pseudo-infection to preserve energy. But while catching the flu makes you want to crawl in bed and pull the covers over your head (and can sometimes even feel like getting hit by a truck!) for about a week, chronic inflammation of the gut creates a vague experience of tiredness that lurks in the background with no known cause and lasts for months, or even years.
The problem is that this inflammation, sourced from the gut, continues to erode the protective mucosal membrane that shields the intestinal lining from bacterial invasion. Much like a castle wall that slowly crumbles from constant attack, the intestinal lining normally keeps invaders out but will eventually deteriorate under endless assaults over time if not repaired. With a thinner lining, more microbial byproducts and even whole bacteria can pass through the stomach wall, which keeps triggering an inflammatory response by the immune system in a vicious cycle. Through this process, inflammation contributes to general feelings of fatigue, tiredness, and exhaustion for many people.
The Stress Response to Inflammation
Under poor gut health, the pro-inflammatory molecules, known as cytokines, start to circulate in the blood and affect other organs, such as the brain. This chronic inflammation builds an ongoing stressor for the body, which uses up energy and resources to protect itself. In addition, the cytokines can impact the hypothalamic-pituitary-adrenal (HPA) axis, a part of the nervous system that coordinates the body’s reaction towards stress, controls mood, and regulates the immune system.
The HPA axis also governs our circadian rhythm by releasing cortisol, a hormone that’s part of our built-in alarm system. Flattened levels of cortisol can lead to insomnia, burnout, and fatigue. Elevated inflammatory cytokines can also increase the risk of mood conditions like anxiety and depression, which can exacerbate feelings of tiredness and exhaustion.
While the relationship between fatigue and the gut microbiome are still under debate, we know that there’s some connection between gut health and feeling tired. As new studies come out linking gut health to the brain and how that relationship plays a role in feeling like you’re running on an empty tank, impact on our energy levels may be just one more way gut health influences our daily lives.